Transient Stability Analysis of Inverters Considering Synchronization and DC Voltage Control Interaction

Renewable power generation is constituting a new power system. However, the system stability is influenced by the increasing proportion of power converters. The transient stability involves system nonlinear characteristics and is difficult to analyze. The Takagi-Sugeno (T-S) fuzzy model has been used to facilitate the transient stability analysis of synchronization control. However, in two-stage inverters, the time scale of DC voltage control overlaps with that of the synchronization control. System stability should be discussed considering these two control dynamics. This paper investigates the large-signal stability of two-stage grid-connected inverters in the synchronization control time scale. The T-S fuzzy model is established considering the dynamics of DC voltage and synchronization control. The Lyapunov stability and the domain of attraction (DOA) are discussed for different system parameters. Finally, simulation verifies the effectiveness of the model and stability analysis.